Nortel Circuit Card, Installation Manual, Page: 72 / 908

Page 72 of 906 Overview
553-3001-211 Standard 3.00 August 2005
Serial Data Interface (SDI) cards
The NT8D41BA QSDI paddle board provides four bidirectional
asynchronous serial ports for the system processor, and the QPC841 QSDI
card also provides four. Any device that conforms to the RS-232-C serial
communication standard can be connected to these serial ports.
The QPC513 ESDI card provides two fully synchronous serial ports for the
system processor. The ESDI card communicates using the Link Access
Procedure Balanced (LAP-B) synchronous communication protocol.
The electrical interface uses either standard RS-232-C signals or a special
high-speed interface that combines the high-speed differential interface of the
RS-422-A standard with the handshake signals of the RS-232-C standard.
The RS-232-C interface is normally used when data rates are less than 19.2
Kbps, and the cable length is less than 15.24 m (50 ft). The high-speed
interface is used when the signal rates are greater than 19.2 kbps (up to 64
kbps) and/or when the cable length is greater than 15.24 m (50 ft).
Table 9 shows compatibility between the three SDI cards and the various
switch options.
The NT8D41BA QSDI paddle board does not have a front panel. It mounts
to the rear of the backplane in the NT5D21 Core/Network module, and does
Table 9
Serial data interface cards
Compatible System Options
Card Ports Port types 51C, 61C 81C
NT8D41BA 4 RS-232-C asynchronous X X
QPC841 4 RS-232-C asynchronous X X
QPC513 2 RS-232-C synchronous or
high-speed synchronous* X X
*
See the section on the QPC513 card in this manual for details on the high-speed interface